Smelting-furnace



H. G. AND W. R. WARD.

SMELTING FURNACE.

Avmlcmon FILED ocr. 4, 191e.

1,351,451 Patented Aug. 31, 1920.

4 SHEETS-SHEET l.

u n i mi. 1VY s t N 4@ I) i l AKAI) U f 4f u sf if.' a

R. G. AND W. R. WARD.

SMELTING FURNACE.

APPLlcAloN man ocr. 4. Isls.

4 SHEETS-SHEET 2.

Patented Aug. 31, 1920.

fu if.

lliam Mrd.

R. G. AND W. R. WARD.

SMELTING FURNACE.

APPLICATION FILED 0121.4. 1916.

Patented Aug. 31, 1920.

4 SHEETS-SHEET 3.

VMM/V R. G. AND W. H. WARD.

SMELTING FUHNACE.

APPLxcATIoN FILED oc.4.,1916.

1 35 1 ,45 1 Patented Aug. 31, 1920.

4 SHEETS-SHEET 4.

frz Ver? Zar/d:

Q l' 7 e v y R i R By zerr #ttyl I t diagram lines illustrative of Certain stru@ tural relations and operational features hereinafter explained.

Fig. a is a detail view supplemental to Fig. and` explanatory of a preferred arrangement ot the peep-hole deviee.

l*`ig's. 5 and (5 are diagrams illustrative oi' certain functions and relations of the hearth-walls of the l'urnare-hearth, and of the mode of action thereof in connection with other parts and features ot the oomplete furnare.

Figs. 7 and 8 are diagrammatic plan views,-f.irawn to a small scale and correspending.r with Fig. 1,-tor illustrating some modifications ot the hearth ot' the furnace.y which are permissible in some instances. within the purview of our invention.

Similar reterenre eh a raeters designate like parts in all the views.

The drawings illustrate the working chambers and also various details inelosed within or by a framework or easing whieh is arranged to he water--eooled throughout. This frame or rasinkgr is also shown made up in lialres. whieh may be constructed separate. and afterward detaehably connected together by bolts, or preferably by rivets whieh ran be readily eut away and replaced by others` as oei'asion may require. These various features, together with the preferred organization oi wall-plates, water and air chambers or spares, circulating* and heating pipes, and other and similar tea tures. are elearly represented by the lines of the drawings, Figs. 1 to ale.y inclusive7 so that only a brief description thereof in detail will be now reouiredu esperially since those improvements. so far as the saine are not defined in the elainis hereof. are intended to constitute in part the subjeetsmatter of other applieations to be tiled by us and eonrurrently pending herewith.

The tornare is shown in Figs. 2, 8. 4T resting upon a base or foundation, l, whit-h, in prat-tive, may be of any suitable and eonrenieut rharaeter. rThe framework is arranged to iuelose an elongated chargerhaniber. (l, and when made in this form, :'onsists of a water-jaelet shell comprising the hollow side-walls, fm2, my, and the endwalis f/r. m3. A series of horizontally lorated water-cooling' and air-heatingV iiues. ai?, 49. are loeated within the water-jacket walls oi' the smelter shaft. or vharge-ehanibei'. t'. whit-h is the inner ore-earryingn shait o` the snulter. and the sidewalls of which. Si. are vertieal. At the base oi the rhaniher C. the. wallsiih. are inwardly ronrergin;4 upon the euri'ed lines, to form the I.'harire-supporting hearth 3g of the furnace. This hearth` roniprisingl the walls 3 and 3i'. Fia'. 2. is ealeulated to support and autoinatii-iilly sustain the ore in the turnaee.- when tuily charged and during operation,-

at and above a certain eective focal point. as l, Fig. 4, and for this purpose said hearth-walls 8, 3"", are preterablY of the shape in proiile, of a parabola. n opening, J, in the furnace-hearth leads direttly down into the iuiobstriwted eonibustion chamber or biu'uer-ehaniber. F5V which is thus'loeated below the inwardly converge ing curve-Il or parabola shaped base or hearth of the ore-earryingDr shaft ot the furnace. Said hearth-opening wall usually be temporarily closed by a charging' grate as (i, while charging and blowing-in the i'nrnace. The erueible of the iurnare is shown formed of two parts 5b, 5b and o", o, designate. the slag and bullion tap holes, respectively; during operation the tap holes will be partly or whoily stopped from time to time as oerasion may require. series oi oppositely-disposed and upwardly i11- eiined burners, H, H7 supply the gas or raporized mi..3ure et oil and air required as fuel; these burners are shown fitted with special air controlling fieviees herein after more fully described. A series :of withdrawable telescope peepers li, l', are

provided through which to observe the state of the combustion and thus aid. in

controlling the operation of the furnace.

The charging grat-e, (i, may lie made oi iron, or in some eases of slag east into `shape and placed temporarily over the opening .l in the base oi' the ore-(farrying shaft. and above the combustion rharnber if: Lo pre- Vent the ore passing through sueh opening into said chamber until such time as the shaft shall. be sutlieiently illed with ore to develop, by its weight and downward pies-` sure. the inward jam or thrust resulting from the active principles embodied in the inwardly Curved or parabola shaped ronverging hearth-walls, 3b. 3b. as indicated by the theoretical tension lines in Fig. afterward the grate will be melted out during1 an early stage of the process ot biowing-in the fui-nare. and is not replaced aga in until the furnare is blown out and has to he recharged. The usual ore-eliargin,"ldoor may he loeateil at or near the top ot the `furnace, whirh may also have a. suitable smoke tine or stack, as 2, The main airpipe #La has two branches, ib. 4., eonnertiug with the air chambers..l 4d. Lid', from whieh the air passes through the tiues Jin. it". to the chambers 4f, 4f. and 4g. Air and them-e throiffg'h the burners ll, il", to the combustion Chamber F. rater tanks mi. m" ina).r be loeateil above the level o the upper ends of the water-jackets of the fumare. and may be eonneeted tl1ere.'ith by the pipes` m, m5 and m", mf for seziurinef a vii-ruhr tion of water in the water-jarket spaces oi' the turnare framework.

ln the preferred embodiment of our invention herein illustrated, one of the imliti lli;

n i .nti

lli

responding' mid-portion of the length of smid heurth-opening. Therefore in Some enses, esperully in furnaces ol exeeptionnlly large size,-it Inny be l'ound desiruhle in prnetiee to Ineke the end walls of the l'urxnn'e oil only n slightly curved 'forni o1' even in the forni ot' Het transverse walls, :unl to loeoie surh wells :Lt or relatively neer the ends ot' the elongated heurtlropen ing; in this ense, of eourse, the said elonguteil sind I )zLrullelly-ilisposed portions or zones of the furnueeheurth will constitute nem-ly or substantially the whole extent of the heurth- 'n.lls, and thus in some instanres the henrth-wull.Meonsillered es u whole,- nnny he :suiil not to be so exteinled as to torni :l voniplete ein-uit. For illustratingl these tentures. ."elerenve is nunlo to Fig. s, "honing in plun View :ovl on n nnnlll ernh, n induino oi (he slioht ly i-nrre'l end-walls, :Lp :unl to hij; i, similarly showing the iongutwl howth when lln' i-hurgorhuniher i j l i\,ll ."l 1f" For ronwnh-ine oi' dwrription. we here les-"ritmi the lnrninre-heurtli :is consisting` oi` u bottoni well whieh is :nlupted by oonstrintion und :li-rangement. for both snpporting the elnirge und i'or closing-in, or "renter-ing the nmteriul, and hence this bottoni nieniher muy be properly designated :is n ehuigeuntel-ing" hearth. lt will be understood, however, that in prut-tice this form of turnui'ehenrth (l will be ol such n width in proportion to the width of the ehurge i-hunilier (this rlnirnber beineV sonntiines designated :is the "shulqtf'l or "orwsliuttih ol Quell u degree oi' inclination; :ind :1r ranged with zt lienith-openingr et surh width und proportion, :is will operute in nnj,` given taisef'in rien oi the nature of tho xnuteriul then being` trezitetL-to support the charge ot' ore or broken rock within the charge Chamber duringr the time while the mid-part ol' the 10nd whieh is directly over the hearthopening and between the oppostely disposed )arts of the furlmee-l'iefirth well or walls. hns the weight of the charge operating;r in eonnoetion with the eluii'go-eentering bot-- toni wall, gradually und properly closes to gether the lower pnrt of the Charge in a progressive manner as the fusing operation pro eeeds. The inner portion or zone of the materiel thus subjected to the closing-in or charge-centering Ifiction, (as specially illustrnted in Fig. 5) may be said to comprise somelnateriul (as at p7, p7, l*`ig. 5), contiguous to the cooled Walls 3", 3"', and other materiel (its :it p", 79", Fig. 5) which is ad jacent to the central fusing-Zone and is in a state of incipient fusion, whereby it is softenedand made more mobile.

The erossseetion forni or outline of the hearth-veli is designated as the role thereof, and ,this vprofile, es the line 3", 3"', Gg, G, is inclined downwardly toward the hearth-opening, and is preferably curved, so that the hearth will be not only inelined but :ils-o ronenvell, unil thus will not; only snpport the i-lnnge, but will ulsoffunil :silnul` tnneoUslyV-i'lose together u` lowi- :unl outer portion ot' th(I Chorin ilurinig.l the losingy :Lwuy ol' the niiclpnrt ol sulfh lower portion within :i eentrul 'Lone thut le lirer'tly :Lbove the heurthwn'ienini; und nlso (lireetly be tween opposite portions oi' the henrllrwnll circuit. hor instsu'n-e`r in Figi, o, the dotted line yi between the dotted lilies p8, pw, show the height ol the span-e or zone within whirh the henrhwnlle il", 3"', nre iin-lined, und the lusingf-zonl, will be liwfgt between Huid wells. or rif'rut. nn-'l inuinly within the suine reriiul nouv. n" orrupiwl by the luwirllrog-ening d.

ln vongnwtion with llnvlnrljg'e-suppoilion :wel enh-rino lnnrlh'will'v mul thaw 'Alon nihil lnullli oghurinj Wenen ilwnl. thi o"l Vivir. r1 i in ,ifo-1i"- 'rrhh-h :lral iol-.elwi wn'l mir linnei'eietf-lv o Illihwmh-opvniinr, fn'l th'.- iil burners of.' :i puir :1re :irlungfwl in lianes-,orso pnirans relutively to enc-h other while wnh :lirmt ell to Amid henrih-openini1g :mil is se.}-,:iintel rf 'uluble by :nliustnunt or otherwire for properly combining the thnnes therefrom :Anil then. or thereby, proiii'tinf the vom binexl llnnief---wliirh ther ronstitutes n fus ing-llnnnL-upwnivlly throuejh the henrthopeninif into n {hebrew/ione whirh uhove sniil henrth opening'. ln wine inslnnies., ifh e. regulation muy he .-llwtml by :in nd isnn-n! o? one lun-nor ol' the piiir relative-ly o, tlvk other. :lnfl thus: also regulate both i poetion unl the intensity oi the eo1nnml ilrxine. or oi the` hotist region thereof, rhrtrel-f. on te .rnilfwei'sr :lireetiointo Suid bottom opening und fnsingj-Zone. In other words. it' one of the burners lil is regir l:=te:l by the erenlr 5T to very the intensity ot' the thune, the other burner H remaining eonstnnt at the time, the hottest zone will be shifted either toward or :iw-uy from the lun-iler ll. :infl obviously if one poil' ol' opposing burners ll and ll is regulated to very their intensity while :i adjacent noir runnin ronstent, the hottest zone will be shifted either toward or away from the first seid pair ot burners.

The burner-cheinber` F, and the construction and arrangement thereof with and rela.- tively to the turmoil-hearth. the metal-receptacle, the jet-burners :ind the Water-Walls, constitutes one of the leadingr features of our present improvements. In these arrangements, the receptacle F is located relatively Close up underneath the hearth-opening, J, while the burner-chamber itself is broadened out into the two op1 ositelydisposed bays, as 6"', 6"', located beyond or outside of the normal range or path of the falling stream of metal and slag. Said bays or side portions of the burner-chamber are indicated at 6, 6c', Fig. 4, being located under the inclined loWerWalls 6, 6b, respectively, of the water-cooled furnace-hearth; thus the be y space 6 is bounded or closed-in by the angularly-disposed walls G, 6, of which the latter, o, constitutes a walhzcne for receiving a series oi' inclined burners, as

which are or may be removably and adjustably fixed therein by means of a suitable screw connection at 8l.

The ai1'and-uel jets, as H, ll', (Fig. d) issue with a relatively high velocity, and have a spreading form as they come together along the mid-line Y, and so mingle and combine in an intense combustion which, though beginning in the chamber' l" does not reach its maximum until carried well up through the hearth-opening l and into the fusing-zone within the hearth-Zone ofthe charge-chamber; these actions and effects are indicated in a diagrammatic manner by the dash-andfarrow flame-lines in Fig. 4. In practice the impact of said spreading streams or jets.` 8, 8. while operating to direct the main portion thereof upwardly in a concentrated manner indicated at 8d, also diverte or deflects some portions laterally and also downwardly,-this latter action being indicated at Se, Se. with the result of filling the chamber C with mixing gases and flame having a sufficient heat to prevent a teo large upward radiation of heat from the mass of molten metal, or of metal and slag, in the receptacle E.

Thus the arrangements and modes of action and coaction herein set forth, effect the smelting of the ores vin a fusing zone which is within the described hearth-zone, and the melted materials after descending through a flame-filled chamber are then collected in a receptacle and there subjected to a protecting llame and heating from above, there by effecting in some respects, a continuation of the reduction-treatment of the melted materials; this supplemental treatment. therefore. is analogous to the operations in an air-furnace of the well-known reverberatory kind. since the flame-filled chamber F serves as a protectin roof above the bath in said receptacle t.

The proper proportioninr; of gas and ain-or of air and oil, as the case may be.- may be readily determined and adjusted by means of the very simple regulating mechanism of the burners as shown. In practice. the operation of the furnace may be readily ascertained from time te tinc by means` of the peep-holes illustrated. These peep-hole devies are designated as telescopic. since they are tubular and are arranged to be easily Withdrawn for adjustment or repair.

l? or more clearly illustrating one of the features of the furnace, and also the mode of operation of the water-cooled metal hearth-walls, one of these walls is shown in the diagram, Fig. 5, marked off into successive zones, el, 22, e, which are disposed parallel to the hearth-opening J, and which, from the upper 'zione e to the lower zone z3, are of successively-increasing curvatures transversely thereof. This series of Zones, ihercfine, may be said to have, also, a. successirely-increasing angnlarity of position with reference to a meridian line, as y, located centrally of the charge-chamber C, or of the bottom opening J. The material on that side of the charge, (that is, between the curved hearth-wall 3l and the outer-line w representing `the boundary oi' the unoccu pied fusing-zone), is guided inwardly by said wall Il, so that during the descending movement of the charge the outer portion thereof which is contiguous to said wall, will be gradually bont inwardly while the inner part of this saine, portion is being continuously fused away adjacent to said boundary line in the diagram, Fig. 6, it will be noted that the inner and =voncaved surfaces of the two oppositely disposed hearth-walls 2lb, lb, respectively. are located in substantial coincidence with symmetrically and oppositely assed ares of the parabolas p2, p2. In this diagram, said hearth-wall arcs are also .shown l ating between them a hearth-opening d, and having the narrow inner zones thereof. as 31. 31", tangential to lines p12, p12', which substantially coincide with the normal :ingle-of-repose of the material upon the metal surfaces of the` wall. Also. it will be noted that taking the foral point l as a conter. the are p (Fig. 5l oc upicd by said heartlropening is sul istantially the onefourth part of a circle. lnt in practice, this angle or spare occupied may vary somewhat from said proportion but should preferably correspond with en are of between one-fifth and threefifhs oi' a circle. By these means, the angular relationships of the said hearthopening and the hearth-wall arcs become organised in sufh a peniliar manner as to provide more fullyY for an effective support of the charge while the lower and outside portions thereof are slid downwardly and inwardly upon the metal surfaces of the henrth-walls. in connection with the fusing out of the midportion at the base of the charge.. as already described in connection with 1rligs. il. to ln this peculiar organization of the furnace-hearth and the several features and components thereof.y it will be understood that the operation of the furnace af. regards these features is Jfacilitated by the maintaining of the said metal-surface hearth-walls in a` relatively cool condition for which purpose an :imple amount of circulating water should be provided. thereby maintaining a constant status or relationship between the hearth-walls and the matedii" llO

rial direetly supported hy and sliding on those Walls.

In the normal operation ol the furnaee the rharge ot' material in the furnai-e-ehamloer is supported hy the ltaid'earryiner hase or hearth-Walls. as 32 3" and the mid-portion ot the material is prevented from falling through the bottom opening, il, hy the fusing together of the material immediately joining' the Al'oral zone 14, this resisting' el'- feet taking place in ronneetion with the peeuliar supportive af tion resulting from the eonstruetion and relative disposition of the said oppositely disposed lioltoin Walls 3j, 35.

ln earryingr out that part of our invention which relates` to the blowing-in of the furnaee,-to begin the smeltingir of the eharget the perforated and fusible charge-supporting grate is plated and extends over said hearth-openilrr for initially supporting a mid-portion or the rharge, and the ,series of enacting burners loeatetl in the burner-ohnmlier are arranged and operated for concentrating the llames thereof against and through .said grate for thereby fusing down said grate and stabilizing (hy heating) the mid-portion of the eli-arge while this portion is supported ivy the fusible grate. The effect of these operations is to staliilizie to a` Selfsupporting;r rendition (as against gravity and the pre-sure of the rharge). said mid portion of the charge, hy projeeting heating llames through the perforations4 et the `errate, and finally the fusing llames will he inereased to the point of meltingr down the grate, after whirl] the snielting operation will normally proveed in the continuous manner already deserihed.

During a eontinued operation of the furnaee, and owingP to the features alloro indirated, and alsoiowingr to the oppositely inclined arrangements of the fusing jets deliveretl through a pair of llurners`r as ll* HQ (Fig. l), the fusing;V jets coming together on about the middle line1 as y, of the furnace naturally mingle together and are foi-eel up Yardly through said bottom opening .l and thus roaet together and operate with the greatest intensity in a foral :cone 'inmediately surroundiimlr the focal point at P so that in praetiee the material forming the lower part of a eharge will he fused or eaten a Tay and thus leave the extremely lower end of the eharge free for the two side portions thereof to gradually elose together toward the said foral zone, this artion oreurring by a Vsliding movement of. the eoml'iined material with a turningr or `shiftimear offer-t, whereby the said side portions of the charge slide downwardly and inwardly toward eaeh other hy a morement inwardly upon the paraholieally-curved hottom Walls 3J, 35'. liurinfrlr this normal operation of the fur4 naee should one of the side portionsI of the charge move downwardly with a greater veloeity than the opposite side portion of the eharge, such more rapidly deseending portion will naturally he fused or eaten away as it comes to the fusing zone, or foral zone, and thus by a normal. aetion within the mass of the eharge eause the opposite portion of the material to move downwardly with a greater foree a nel rapidity and thereby, automatically as it were, restore the lialaneed and relatively uniform progressive downward movement of the entire chargrm and, also`r do this with a minimum distnrllanre or irregularity of movement of the material Within the different portions of the mass. The said 'several portions of the material and the eoperative fusing llames therefore eoaet together for the maintenance of the Complete operation ln a eontinuous manner and with a maximum degree of etiirieney.

The foregoing :Virrangements and modes of aetion also provide for a further ohjeet and result whieh is regarded as partienlarly important for the maintenanre of the furnace in Constant operation at a sul'istantially uniform rate ol' aetiou and uith the requisite degree of ettieienry notwthstandinlgr irregularity in the mixture of the material and the oeeasional presence in the Charge of a mass of a relatively infnsilile or slowly fusible ores` or other mineral. For instanee7 should an exceptionally obstinate or refractory mass beeome projeeted down wardly into or through the hottom opening o". the two lun-ners, as ll1 ll', Fig'. Yl, will then operate individually as blow-pipe fusing devil-es -flirertly upon such protruding mass, while the downward movement of (he ehargef-immediately above sueh. oi. lrurted point-is tenniorarily halted through the ohstruetion of the said bottom opening,r as against the upwardly nearing' eondiined flames of the tivo burners, Thus said harners may he said to operate somewhat individuallyr` while zitting `.Vith a romlifned effect upon sueh protruding olastaele or naiss, n'hieh is thus fused and eaten away hy a most intense aetioin sinee the two llames are then roneentrated at a point ennsideraifly below the normal foral point oli the ripper fusing zone. (ln the reduction and disposal in this manner ol any sueh olistrnrtion. the two llamesl as indieated at t3@ Fl. (Figi: l) normally meet again and combiney into an upwardly n1ovinr fusing llame rvhf-ii will gradually fuse or eat away sufh material as may in the meantime rome to owns* the normal fusing' zone, and in this manner gradnally hut rapidly restore the turnale to its proper mode of aetion aul to ille, gradual bringing down of the charge in the more regular and normal manner alreadyr set forth.

The eonstrurtion of the hottom walls 3j, tij. in 'in elongated form 4inl jdie arr y y ment of them in a parallel manner eumlll] of pairs ot said coartfurther advantage and mode ot' action which is one of the objects ot our present invention. Jhon each ot the pairs of burners is operating in the normal manner set torth, ot course the tornare rhargre will he operated upon, and Twill normally (laaiend, equally thro nit the length ol the 't'iirnrwe-liottom. l3nt should there he an obstruction at sonic one point, especially il' near one enil,as, for instance :at the right-hand cnil pair ll, ll', in iig. `,*the charge at the opposite end, (as for instance, at the left-hand end pair H, H'), will continue to descend and the burners to .rorlt normally while such an obstruction at such one point is being fused outu rlhus where a plurality of three or more of the pairs ot burners are employe:l,-with a length of turnzu'e-hearth, or bottom, ot pri-:iper length therefoigfean obstruction at only one' pair ol the burners still leaves a plurality of such pairs 'lier continuing the smelting operation, so that the obstruction does not largely interrupt the operation as a whole, l-ut only reduces the rate or extent of the smelting action.

A further feature of this plural-pair burner arrangement is that during the fusing out as desvrihed of an obstruction at one point, an adiacent pair ot burners continues (normally and usually) the fusing ot' the charge in that part o'f the normal fusingzone which is just one side of such obstruction, so that the obstructive mass is thus suhjected to a compound, or complex treatment, applied on one side and above theL heart-lr walls hy the combined flames ot one pair of burners, and in (or below, as the case may he) the hottomopening, J, hy the concentrated action concurrently of the two individually-acting: burners of another pair of burners. ln order to secure this complex action in the liest manner, the furnace-hearth is preterahly made relativelylong, so that in the charge-chamber, the column or charge of broken ore or rock, will readily more within itself sulliciently for properly supplying,- by a continuing descent,-the ore to all that part ot said hearth where the burners are operating normally within the said normal fusing-zone, notwithstanding a temporary stoppage ol such descending; or supply movement in. that part ol' said chai-gerhamher which is immediately above the obstructed point. Thus while the obstruction is attacked from opposite sides in such 'portion as may extend below the hearth-openingr J, it is also attacked Vlrom another side in that portion thereof which is above such heartily opening.

From the foregoing description as illus trated, it will now he evident that in the preferred torni and arrangement of our improved furnace, the mode of action is norliincd with a plurality inf: burners, secures a mally ol' an intermittent hind in which, in each ot the dcscriliell hui'nc1-zoues,-tlie fusing action changes hack and forth along the length ol" the hearth, in acci'irdance with the variations in the character of the material and in the rate of supply thereofyl`hc improved means which we have devised tor blowing-in or inauggiurzuiiig the operation of the sineltiug lurnare, ronsists of a support which permits the lusingflanics to pass into the charge. while being itself reduced or melted out. The lusilile or analogous support is inserted across the hearth-openinf, and has perforations or spaces through which the flames may pass upwardly into the charge and thus partially fuse, or make adhesive, a lower layer ot' the ore betere the support or grate falls down. One suitahle 'torni ot such a support is shown in section at il', Fig. 2, and may he in the form of a grate havingr side-hars 7, centerhar T, ril'is T, and flame-spaces Td. After starting the burners, the air pressure should he raised to a point for gettingr a high intern sity oi' the heat, sullicient to melt out the said support, but not to do this until atter the material directly above shall have been heated at least to the point of incipient fusion. ln this way the material may he said to he stabilized in that part of the charge which is directly over the hearth-opening, which thus, liy a partial fusion, is made sutliciently seltsupporting to hrirlg'e=.ioross,-as by an archfrom the hearth-wall on the one side, as El, to the hearth-wall on the other side, as 31", and thereby prevent a premature settling down ol the charge. A further improvement is to malte the said 'initial load-supporting member, as (l, oi' a slag;r l composition which, on melting, will mingle with the slag from the charge, and so aroid any adverse metallurigical effects. In practice, such supports may he made in one or several pieces, and also may be cast into suitalile torni.

By care in replenishing the charge, and from time to time observing,r the upper sur- 'face thereof, the furnace attendants can readily discover the existence and the location ot any considerable obstruction in the hearth-opening by notinpr the inequalities in the descent ot the charge in different portions thereof, so that,-in accordance with an experience readily gained in operating upon any particular character of material,- they may Yfrom time to time Vary the relative lun-den and downward pressure upon dirl'erent portions in the length of the hearthwalls, by suitably varyingv the heights of the respective portions of the'charge. Similarly, in the absence ol any such obstruction, the attendants may ascertain by means of such observations in what part of the length ot the hearth the normal progress ot' the smelting operation is proceeding most rapidly, so that the supply of air and fuel to the relill) lll) spective pairsoi' burners may be properly regulated from time to time as found desirable for equalizing or suitably regulatingr the rate ol' oresreduction throughout the len'fth of the furnace.

l aving thus described our claim:

l. ln ai smelling furnace oi' the eliaracter desc; iiieih the rombination ot' a horizontally elongated charge chamber havingP the lower part oi their walls downnariil)Y and inwardly curved to form a 'nrnaheartli provided `with a central elongated hearth opening haring a width 2greater than its vertil al depth :nd oppositely disposed npwardlv and inwardlyY pointing enacting burners arranged under said hearth and disposed in opposed pairs and adapted to combine their llamesy at a point vinst beneath said openingvr and to project the concentrated tlaines up through said hearth opening to points considerably above the opening.

2. In a smelting furnace et the character described, the combination of an elongated charge chamber havingy the lower part ol' their wells inwardlyy inclined to torni a l'urnace-hearth provided with a central elongated hearth opening' having a width three times greater then its vertical depth; and enacting burners arra need onder said hearth, on opposite sides of the principal medial vertical plane ot' the furnace, and disposed in opposed pairs and adapted to combine their llames and to project the combined flames up through said hearth opening and concentrate them at points considerably above the opening.

3. ln a sIni-iltifngr furnace ot the character describeih the combination of a horizontall),Y elongated rharge chamber having the lower part ot their walls downwardly and inu wardlv paraboli:alliv curved to form a fin'- nace-hcarth provided with a central elon- ,eated hearth opening having a width three times greater than invention, We

its vertical depth; a burn-er -fharnher beneath said hearth; and upwardly and inwardlg7 pointing 3o-acting burnerse arranged under said heartln on opposite sides of the principal medial ver tical plane of the furnace, and disposed in opposed pairs in planes intersecting at right angles said medial plane, and adapted to combine their flames and to project the combined llames up through said hearth openin il to points considerablyv above the parabolie` focus line oi said hearth.

L ln a smelling' furnace ol' the character desfribed, the combination of a horizontally elongated charge chamber havin;r the lower part of their walls downwardljiT and inwardlv pai'almlically curved to form a fun nare-hearth provided with a central elongl'atrgd hearth openinpr havingV a width three times greater then its vertical depth; a burner chamber beneath said hearth; oppotely disposed upwardly and inwardly 'Y Vino' rei-acting burners arranged under 'l hein-th on fiipposiie sides ot the princiieil medial Vertical plane ol the tnrnaee, and disposed in opposed pt irs in planes intersect ingr at right angles d medial plane, and adapten f combine their llames and to pronirrt the foinliine-:l llames up throiiifh said hearth op; iin; to points considerably above the parahoiic iii us line ot said hearth; and means im' ,separately regulating said burners thereby to EHermit position of said coinhined llame.

5, ln a smeltingf l'nrnace ol the eliaractcr deserilied, the combination of a horizontally elongated charge chamber having a furnacehfxarth proi'idid with a central elongated hearth opening; burners arranged to protheir combined llames up through said hX rth opening' and means for positioning fri. said llame.

t3. ln a sini'fltine' furnace oi the character descriheih the con'ibination of a horizontally ein; ted lnx-fe chamber having a furnacev he l provided with a central elongated he rtii opening; ,burners adapted to combine their llames and to project the combined flames np tlirongfh said hearth opening: and means t' seprjiratelv regulatinr said burn- 'o ici-mit positioning ot said ,()l' ers tlifircb'wr L combined flume T. ln a smfcltinp; YFurnace ot the oharaeter feserilwfh the combination ol a horizontally elongated charge i"hamber ha vingy the lower par! oi" their walls dowiiwardlyY and inivardi'-,Y curved to loi-m a li'urnace-hearth pro* vided wth a central elongated hearth openi .p'positely disposed npwardlj7 and inwia rally pointing enacting` lnn'ners arranged :Slider said hearth, and adapted to Coi'nhine their llames and to projet the combined llames up through said hearth og'ieninnf; and means' for separately regulating' said burners-z therelij,Y to permit positioning ot said `rombincd llame.

H. ln a sineltingf f"urnace of the charaeter described, the combination oi a franieworl; haring walls providing,r a fluid containing space therebetween and forming a charge fhaniher; heating means adapted to direct heating medium into said chamber; horizontal flues passing through said space and feeding" said means.

I). ln a sinelting furnace ol' the character described, the combination oi' a framework providingv a fluid containing space and tormiig a rlnrgge chamber and a hearth at the lower part ol' the charge chamber heating* ineens adapted to direct heating llame into :fziid rh'frrnber; and horizontal air fines passing throngh said spa'e and 'feeding said means.

10. ln a smeltinsr furnace of the character described`r the combination of a framework having walls providing a space thered elongated charge chamber wardly and upper charge chainbetwcen and forming an and inwardly 1n-t ber and a downwardly elongated charge chamber provided with double walls forming a space between and ciined hearth at the lower part Vof the charge; having their lower part forming a downchamber and a downwardly and inwardly swardly and inwardly inclined furnaceat the lower part of Vthe charge Ychamber surrounding an elongated hearth; burners adapted to combine and direct heating flame through said opening; anV air chamber partly surrounding sai i space and feeding the burners; and ues .Y passing through said Vspace and feedingV the air chamber.V f

11. In a smelting furnace of the character described; the combination of a framewor having two-plate walls'providing afiluidcontaining space therebetween and forming a lower burner chamber, an upper char e chamber and a downwardly and inward y inclined' hearth at the lower part of the charge chamber surrounding an elongated hearth opening between'the chambers; burners adapted to Vcombine and Vdirect heating flame through said opening; an air chamber partly surrounding said space and feedinclincd hearth ing the burners; and horizontalY flues passing through said space and feeding the air chamber.

12. In a smelting furnace of the character described, the combination of a horizontally provided with a space therein and a'furnace-hearth; oppositely disposed upwardly and inwar ly pointing opposed co-acting burners arrange under sait hearth and adapted to combine their flames and to project the combined flames up through said hearth opening; a heating means for Said chamber; a heat transferring fluid in said space; and horizontal air flues passing through said fluid and feeding said means.

13. In a smelting furnace of the character described,l the vcombination of an elongate charge chambenprovided with double Vwalls Yand a furnacehearth :provided with acentral opening; burners arranged to project flames up through said hearth opening; a heatV transferring fluid in said space; and horizontal air flues passing through said fluid and feeding said burners.

14. ln a smelting furnace of the character described, the combination of a horizontally elongated charge chamber provided with double wallsV forming aspace between and having their lower part forming a downinwarolly inclined furnacehearth provided with a central hearth opening; reacting burners arranged under saic hearth and adapted to combine their flames and to project the .combined flames up through said hearth opening; a heat transferring fluid in said space; and horizontal air flues passing through said fluid and feeding said burners.

15. In a smelting furnace of the character described; the combination of a horizontally d `under said hearth iearth provided with a central hearth openlng and a burner chamber therebeneath; 0piositely disposed upwardly and inwardly iointing opposed reacting burners arrange and adapted to combine their flames and to project the combined flames up through said hearth opening; a heat transferring fluid in said space; air chambers partly surrounding said fluid and said burners; and air llues passing through said fluid and feeding said chambers.

1G` ln a` smclting furnace of the character describcrh the combination of a horizontally elongated charge chamber having a hearth provided with an elongated hearth opening; and au elongated fusible supporting member extending over said opening.

17. In a smelting furnace of the character described, the combination of a horizontally elongated charge chamber having a furnace hearth provided with an elongated hearth opening; an elongated fusible charge supporting member extending over said opening; and means for fusing said member.

18. In a smelting furnace of the character described; the combination of a` horizontally elongated charge chamber having a furnace hearth provided with a central elongated hearth opening; an elongated fusible charge supporting grate extending over said opening for initially supporting the charge; and burners adapted to project. their flames up through said hearth opening.

1l). la a sinclting furnace of the character described, the combination of a horizontally elongated charge chamber having the lower part of their walls downwardly and iuwardly curved to form a furnace-hearth provided with a central elongated hearth open ing; an elongated fusible charge supporting rate extending over said opening for initially supporting the charge; an upwardly and inwardly pointing coacting burners arranged under said hearth in opposed pairs. and adapted to project their combined llames up through said hearth opening.

20. in a sniclting-furnace of the character described, in combination; an upper chargecliamber; a lower lnirner-chamber; a horizontally-disposed furnace-hearth interposed between said upper and lower chambers; and comprising a pair of charge-supporting and transverselyY curved metal surfaces constitilting hearth-walls and located in substantial coincidcr "i with symmetrically and op V)ositidy-disposed arcs of a parabola. and haring between thein a hearth-opening occupying a mid-are of the same parabola and corresponding with an arc of substantially onefourth of a circle, said walls also having a narrow inner zone thereof tangential lo a line which substantially coincides with the normal anglebf-rcpose of the material upon the metal-surface of the wall.

2l. ln a snielting-furiiace of the character described, in combination` an upper chargechaniber; a lower burner-chamberg a horizontallfvkdisposed Jfurneufe-liearth interposed between said upper :and lower clian'ibers,and comprising a pair of cl1argasupporting and transverselyY curved nietal surfaces constituting' hearth Walls and located in substantial coincidence with .syininctrically and oppositeliY disposed arcs. respectively, of a parabola. and ha ving,r between them a hearthopening occupying a nud-arc of the same parabola and corresponding` with :in are of between two-lifths and tlneelii`tlis of a circle. said Walls also haring a narrow inner zone thereof tangential to a line which substantiallycoincides with the norinal angle-ofrepose of the material upon the metal-surface of the Wall.

In a snielting-l'urnace of the character described, in combination, an upper chargechaniber; a horizontaily-disposed furnacehearth located below said chan'iber` and coinprising a pair of parallelly-disposed chargesupportin l metal-surfaces which are trans- Versely-curi'ed and constitute hearth-Walls located in substantial coincidence with syminetiicalllif' and oppositelydisposed arcs of a parabola, said Walls having between them a hearth-opening occupying a mid-are of the saine parabola and correspon(hierr with an :irc of substantialljyr one-fourth of a circle, and ine-ans located below said furntu'e-hearth and arranged for applying fusingdlaines upwardly through said hearth-opening.

23. ln a snielting-furnace oi' the character described. in combination, an upper charge chamber; u lower burner-chamber: a horizontally-disposed furnace-hearth interposed between said upper and lower chambers, and comprising a pair of charge-supporting and eharge-centeriiigir hearth-wal symmetrically and s:ppositely-disposed and having between I'heni an elongated liearth-oiening. un elonga ted fusible charige-supporting' inember eX tending over said hearth-openngr for initially supporting the charge. and fusinpl ineens located in the burner-chamber and arranged for stabilizingq by heating, a inidportion of the charge while supported by the fusible-member. and for then melting down said fusible means.

2l. In a siiieltiiig-flii-iniee of the character described, in

chamber; a

mentally-disposed fur combination,

an upper chargelower burner-chamber; a horibetween said upper and low comprising a pair of charge-cent@ and oppositely-disposed e thein an elongated hear gated fusible tending ove tiallyv enacting bu chamber an heating a mid supported by t mel ting 25.

chamber .j a

Zontally-disposed furnace sujriporting nace-hearth interposed er chambers, and

charge-supporting and ring liearthwalls symmetrically r said hea riiers located d arranged 'fo nd having between tli-opening, an eloncharge-supporting rth-opening for inithe charge, and

grate exa series of in the burnerr stabilizing by described, in combination? an upper chargelower burner-chamberg u horibetweeii said upper and loY comprising opening for and. a series a cher centering hearth hearth-opening; supporting grate extending -hearth interposed er chambers, and

gie-sup porting and charge- Wall having a an elongated fusible chargecentral oijersaid hearthinitially supporting the charge: of coacting burners located in the burner-chamber andV arranged for concentrating the underside of sa down said a mid-portion of the charge by the fusible grate.

2G. In a snieltin described, in com chamber; a

zontally-disposed furnacebetween said upper and loi comprising a pair ofcha charge-Gente an d the charge;

ing by heati while supper oppositely-disposed them a hearth-opening; charge-supporting memb Said hearth-opening for i flames thereof against the id grate for therebyrfusiiigl grate and stabilizinur j by heating;` while su p ported g1g-furnace of the character bniation, an

upper chargelower hurner-chainber; a. horiliearth interposed 'er chambers, and rge-supporting and ring hearth-Walls symmetrically and haif'ing between an elongated fusible extending over nitially supporting` Y fusing means located in the biliner-chamber and arranged for stabiliztingr down said cooling ineens sistingr the over-heating of ing down of said fusible meniing the inelt RANDoLr WILLIAM g a mid-portion of the ed by the fusible member,

charge and fusible member: arranged for rethe hearth dur- H G. WARD.

R. WARD. 

